Improvement in steam-boilers



Y by means of tubes B B.

' UNITED STATES PATENT @EET-CE.

SIIJAS STUART, OF STERLING CENTER, MASSACHUSETTS.

iIVIPROVEIViENT iN STEAM-BOILERS.

Specication forming part of Letters Patent No. 33,71 7, dated November l2, 1861.

To all whom t rim/y concern:

Be it known that I, SILAs STUART, of Sterling Center, in the county of Vorcester and State of Massachusetts, have invented a new and Improved Boiler for Generating Steam for Engines and other Purposes; and I do hereby declare that the following is a full,

clear, and exact description of the same, reference being had to the accompanying drawings, making a part of this specification, in which- Figure l is a side sectional view of my invention, taken in the line a; .fr of Fig. 2; Fig. 2, a horizontal section of the same, taken in the line y y of Fig. l; and Fig. 3, a horizontal section of the same, taken in the line .e .a Fig. 1.

Similar letters of reference indicate corresponding parts in the several figures.

The object of this invention is to obtain a boiler which may be constructed in an economical manner and capable of generating steam or heating water with a very moderate consumption of fuel. To this end I construct and arrange the boiler and fire-chamber in such a way that the water will be exposed to a large heating-surface and with a fire-chamber of very moderate dimensions, the latter being of annular form in its horizontal section and interposed between two concentric water-chambers which comprise the boiler, the outer chamber being encompassed by a lue from the tire-chamber, and all arranged as hereinafter fully described.

Theinvention has, further, for its object an improvement in the grate of the fire-chamber, wherebyr the admission of air into the iirechamber may be graduated with great nicety and the ashes from the tire-chamber readily discharged when necessary.

To enable those skilled in the art to fully understand and construct my invention, I will proceed to describe it.

A represents an uprighty tube or cylinder which forms the central portion of the boiler, and B represent-s an annular water-chamber which is concentric with the tube or cylinder A, the latter being connected with the former The tube or cylinder A and chamber B comprise the boiler. The lower end of the tube A is of conical form and the inner side of the lower part of the chamber B is of inverted conical form, as shown clearly in Fig. l. The space between the lower parts of the tube A and chamber B constitutes the fire-chamber A', which, it will be seen, is of taper annular form, gradually increasing in width from its lower to its upper end. The tube or cylinder A extends some distance above the chamber B, and is provided at its upper end with a safety-valve C. The upper end of the space between the tube A and chamber B is covered by lids D.

The chamberB of the boiler is encompassed by a jacket E, which may be of metal plate or of masonry. This jacket extends up as high as the chamber B, and it rests on a hollow base f, which forms the ash-pit of the tire-chamber A', as shown clearly in Fig. l.

G G are pump or water-supply pipes which communicate with the lower ends of the tube A and chamber B, as shown in Fig. l.

Theupper part of the space between thetube or cylinder A and the chamber B communicates by an opening @XX with the space II between the chamber B and the jacket E, the space H being a flue, the lower end of which communicates with a smoke-pipe I.

rlhe bottom of the tire-chamber A heilig of annular form has an annular concave grate J beneath it. This grat-e .I is connected by arms a to a central tubular liub b', which is fitted loosely on the supply-pipe G, connected with the tube or cylinder A. The hub b of the grate J rests ou a lever K, the outer end of which is connected to a vertical rod L, which passes up through the space I-I.

M represent gage-cocks which pass horizontally through the jacket E into the chamber B of the boiler. The smoke-pipe I is provided with a damper N.

From the above description it will be seen that the water in tube A is exposed to a direct action of the fire in the fire-chamber A', as the latter encompasses the lower part ot' said tube. The water in B is exposed at its inner surface to the iire in the tire-chamber A', while its outer surface is exposed to the heat in flue Il. Thus it will be seen thatthe water is exposed to a large heatingsurface, and owing to the annular form of the firechamber A the rire of the latter is distributed over alarge area or surface. The grate J by actuating the rod L may be raised or lowered l. The tube A and chamber B, connected by the tubes B and forming the boiler and lire-chamber A', in combination with the jacket E and pipe I, all arranged substantiaily as and for the purpose set forth.

2. The annular grate J, when arranged tc rise and fall, substantially as described.

SILAS STUART. Vtnesses:

HENRY HOWE, LUCIAN STUART. 

